feat(mcp): expose thread workspace inventory

apps/server/src/git/GitWorkflowService.ts

@@ -62,6 +62,9 @@ export class GitWorkflowService extends Context.Service<
     readonly listRefs: (
       input: VcsListRefsInput,
     ) => Effect.Effect<VcsListRefsResult, GitCommandError>;
+    readonly listWorktrees: (
+      cwd: string,
+    ) => Effect.Effect<GitVcsDriver.GitWorktreeInventory, GitCommandError>;
     readonly createWorktree: (
       input: VcsCreateWorktreeInput,
     ) => Effect.Effect<VcsCreateWorktreeResult, GitCommandError>;
@@ -306,6 +309,10 @@ export const make = Effect.gen(function* () {
           isGitRepository ? git.listRefs(input) : Effect.succeed(nonRepositoryListRefs()),
         ),
       ),
+    listWorktrees: (cwd) =>
+      ensureGitCommand("GitWorkflowService.listWorktrees", cwd).pipe(
+        Effect.andThen(git.listWorktrees(cwd)),
+      ),
     createWorktree: (input) =>
       ensureGitCommand("GitWorkflowService.createWorktree", input.cwd).pipe(
         Effect.andThen(git.createWorktree(input)),